Interlocking system for railroads



Se t. 13, 1932. E. c. LARRY INTERLOCKING SYSTEM FOR RAILROADS Filed July 7, 1930 MW ATTORNEY Patented Sept. 13, 1932 UNITED STATES -PATENT OFFICE].

EDWIN c. LARRY, or ROCHESTER, new

YoRKQ SSI NOR TO cENE AL RAILWAY SIGNAL COMPANY, or ROCHESTER, NEW YORK INTERLOCKING SYSTEM FOR AILRoAns Application filed July 7,

This invention relates to a switch machine control apparatus for railway systems and more particularly to a switch machine control apparatus of the dynamic indication type.

In an interlocking system of the interlocked lever type, it has been found necessary to prevent the stroke of the lever being completed until the function controlled by such lever has responded to initial movement of such lever, and further it has been found expedient to lock the lever in an eX- treme position for detector locking purposes. In accordance with the present invention it is proposed to employ dynamic indication current generated by the function apparatus, such as the switch machine, for unlocking the lever and permitting movement of the lever from the half to the full position, that is, from the half normal to the normal'position or from the half reverse to the full reverse position, and in accordance with the present invention it is proposed to employ the same locking means for detector locking as. is

, used for indication locking.' It is-further half reverse position, as the case may be It is further proposed to provide means for effecting deenergization of this stick relay in the event the lever ismoved through its intermediate position, this in order to prevent the operator from very quickly moving his lever from, say, the half normal to the full reverse position, or from the half reverse tothe full normal position, for if this were possible the operator might take advantage of an indication received from a switch machine due to completion of its normal stroke for releasing his lever for movement to the full reverse position.

Other objects, purposes and characteristic features, of the invention will in part be pointed out hereinafter and in part be obvious from the accompanying drawing.

1930. Serial No, 465,853.

Structure into an approach sectionA and a detector track section D, by insulating joints 2, a

track switch S being shownv for diverting traflic into the siding containing the-track rails 3. This track switch S is preferably operated by the switch machine SM, including a motor M and a reversin switch having movable contacts and 6, which contacts are operated upon completion of the operating stroke of the switch machine. 1

This switch machine SMiscontrolled suitable means well'known in the interlocking art, and as conventionally shown by the lever of a conflicting route having contacts 3334 included in the detector locking circuit. This lever L includes'movable contacts 10, 11,112, .13 and 14., the functions of which will be pointed out hereinafter. The lever L is also provided with locking shoulders and 16,

urged to its lower position bygravity and; maybe raised from its lower locked position by the indication magnet .IM, this indication .dium of an indication relay IR in a manner as more fully describedhereinafter. In order to avoid the substantially continuous flow of current through the indication magnet TM there have been provided normally open eners gy saving contacts ES, which contacts may be closed-bythe operator upon gripping the a b, a lever L in the interlocking plant, which over the top of which shoulders are located' magnet IM being controlled through the mewhereas the lower winding of this stick relay IR and the indication and detector locking "circuits receive'their current from another battery B this precaution being taken to avoid against unauthorized crosses butif desired one of these batteries may be eliminated, It should be notedthat the normal, v

half normal, reverse, half reverse and middle positions'ofthelever have been designated N,

HN,B,HRand Lrespectively. Having now described the various elements of the system, it is believed expedient to consider the operation of the system, this 'in'order to more clearly understand its operating characteristics and certain advantages afforded by the novel winding of the indication relayIR, wires 50 1 and C, field winding-4L3 of themotortL-wires system under consideration.

' Operation The switch machineSM has been shown lil'l ts normal ll'lalIl' track pos tion, and the lever L has'be'en shown in its normal pushed- 'in position. Let us assume that the operator wishesto move the track switch S to the takesiding position through the medium of the I "switch *ma'chine SM. In order to do this he -will depress 'the push button PB, and in the event that the;det'ector track circuit is unoc- 'cupied, as manifested by the track relay D1 sho'w'nconventionally by a' dotted line, and

"the track-section A is unoccupied, as' maniiested thrOugh the medium o'f the'track relay TA,-the following circuit for the indication magne't is completed :"beginning at the terminal of' the battery B wire 17, contacts 33 34 of the conflicting lever L wire 18,

' front contact {19 ofthe track "relay DT, wire Q 20, front contact 21 of the-track relay TA,

wire'22, contacts13'23, wires 24 and 25,

energysavin'g contacts ES, wire 26, back contact 27 of the" stick relay IR, :wire 28, coil of theindication magnet 1M, wires 29, 30 and 31,

hand back to the battery 13'. The flow of current in the. circuitjust traced will lift the movable core 32 ofthe indication 'magnetIM,

thereby raising the locking plunger LP to ,a ,position to free, the locking'shoulder 15, pernnttlng movement ofthe lever L from. its

normal position N, :upon which the contacts 13 23 open, and efiect deenergization o'f'the indication 'magnet 1M.

The lever L may,however., be moved to the 'half ireversed position HR even though'the combined indicationand lock magnet -IM is now deenergized, thereby closing the reverse circuit for the switch machine SM,which may be traced as follows zbeginning at the positlvetermmal-of the battery' B ywire 35, contact 11-1-36', wires 37 and R, contact 5 "of the stuck up through the following stick cirback tothe battery B closureof thiscircuit-operates the switch machine SM, and in turn the track switch S, tov

its reverse take-siding position, and when the stroke of the switch machine has been completed, the contacts 5and (Swill be operated .by this, the dotted position of the contacts 5 and snap action to the dotted position. In

G'of the'switc'h machine SM, and with the motor M-rotatingby its inertia in a direction to move thetrack switch still further toward the take-siding position, dynamic current is generated in this series motor M, which dy- "namic'current: may flow through the upper winding of the indication relay IR through the following circuit :beginning at the ar- "mature 89, wires 10. and 46, contact :5,*wires N and4-7, contacts 10 48, wire 49, upper 42and 51 contact 6 of the switch machines M, wires 52 and 38, and back to-the armature39. The flow of this dynamic current eflects ener- 'gization of the indication'relay IR, and with it'scontact 55 once picked up this 'relayIRis cuitc-beginning at the positive terminal of the battery B wires 56, 'and'57, contacts Q12-58, wires 59 -and60, stick contact 55 of the relay IR, wires 61, lower "winding of the indicating relay IR, wires 62, 30 and 31, and

With' 'the-indicat-ing relay IR now energized in response to the'flow ofdynamic-indication currentand maintained up through its stick-circuit, the indicating'magnet IM is energized through the following circuit zbeginning atthe positive terminal of the battery B wires 5'6;and 57, contacts 12'58, wires 59- and 67, frontcontact 27 of the indicating relay IR, wire 28, winding of the indication magnet 1M, wires 29, 30 and 81, and

back to the battery B "Flow of current in the circuit just traced effects lifting of the lock pawl LP, thereby permitting movement I of the' lever L "from its half reverse to its 'full reverse position, in which latterfposition the for the present position ofthe leverL of the interlocking plant tobe operated. Also, the

operatorneed not move this lever immediate ly, for with the indication relay L R energized by a stick circuit it, will remain in 1ts energized position. irrespective of theflow of dynamic indication current.

operator when his lever assumedithe half re verse position -HR.land with the indication relay IR-energized, suddenly changed'his It maybepointed out here, that had "the 2 mind and decided to move the lever-L' back to the fullknormal position, such zmovement would have closed the intermediate contact 14770, and thereby would have completed an energizing circuit for the pull-down magnet 71 of the indicating relay IR through the following circuit :beginning at the positive terminal of the battery B wire 73, winding of the pull-down magnet 71, Wire 74:, contacts 1-1'70, wires 75 and 31, and back to the negative terminal of the battery B Even though the lever L is moved very quickly toward this improper normal position, the pull-down coil 71 will pull down the contacts 27 and 55 very quickly, and force drop cam FD will force the lock plunger LP down between the shoulders and 16. The pulldown coil 71 of the indication relay IR is designed to pull down the contacts 27 and 55 of this indication relay IR irrespective of the flow of conflicting currents in the two windcation relay IR for reasons heretofore given this dynamic indication circuit being readily ings of the indicating relay IR, even though such conflicting current is not likely to flow, so that these contacts and 27 will be very quickly moved to their retracted position,

thereby breaking the circuit for the indicating magnet IM and preventing movement of the lever L beyond the intermediate position.

Not only this, but the operatorwill be penalized for having mis-operated his lever L,

now that he has entirely lost the indication which was manifested by the picking up'of the indicating relay IR, so that the switch machine must be operated specially to obtain the desired indication. For instance, with switch machine now assuming the reverse position the operator must first operate it to the normal position, and he must thereafter operate it to the reverse position to obtain dynamic indication current withthe lever in the halfrreverse position, so that he can, upon unlocking of the lever L, move it to the full reverse position without moving it through the intermediate or middle position.

In view of the symmetrical arrangement of the circuits and contact, it is obvious that movement of the lever L to the half normal position will effect operation of theswitch machine SM back to the normal position through the mediumof the normal wire N, and similarly when the switch machine SM has been operated to such normal position, dynamic indication current will be caused to flow through the upper winding of the inditraced in view of the fact thatit is symmetrical to the dynamic indication circuit heretofore traced.

Although a simple conventional switch machine SM has been illustrated it is desired to be understood that a switch machine hav-' ing many other features, such as reversibiL ity in mid-stroke, as for instance shown in the patent to Howe No. 1,466,903, dated September 4, 1923, and having other desirable characteristics, may be employed. Also, in-" ,ess

stead of employing electric interlocking be-- tween levers, having contacts of all c'on flicting levers included in series with. one of 'the wires 18, 20 or 22, as shown by the contacts 33--34, the conflicting levers may be locked mechanically by suitable lock bars and lock dogs. In other words, well known It is alsov to be understood that although no cross-protection relay. or other suitable protection apparatus has been shown, such apparatus may be employed in the present system, if desired. -Also such apparatus as timerelease devices, and other auxiliary apparatus, maybe added to the present system without departing from thepresent inven tion.

7 Having thus shown and. described-,one rather specific embodiment of the present invention, and having illustrated many of the elements of the system conventionall it is desired tobe understood that this is one for the purpose of simplifying the description of a system embodying the invention,

and that the particular arrangement illus-.

trated has not been selected for the purpose of showing the scopeof the invention or the exact construction employed in practicing the same, and that various changes, modifications and additions may be made to adapt-the inventionto the particular problemencountered in practicing. the same all without departing from thespirit or scope of the invention except as demanded by thes'cope of the following claims.

What I claim as new is 1. In comb'nation; a switch machine for operating railway track switches, a lever.

having a half normal position and a half reverse position for operating said switch machine; and locking means for preventing said lever being movedito the. full normal pos1tionunless'said switch machine has been operated to the normal position and prevent- -iiig said lever being moved'to the full reverse position unless said switch machine has been first operated to the reverse position comprising; a stick relay having a pick-up'and a stick circuit, said pick-up circuit including the armature of the operating motorof said switch machine when said switch machine is being dynamically braked, "andsaid stick circuit including .a contact of said lever closediwhe'n said lever applies operating ourrent to said switch machine to operate it to the last o-pera'tedposition, and means controlled by said stick relay for permittingsaid leverto'be moved to thecorr'espondingfull position.

; 2. In combination; a switch machine for operating railway track switches; a "lever having a full normal position a halfnormal position, a full revers'e'position and a half 94111011, and release 'meanscontrolled by said *machine and locking means for preventing said lever being moved .to :the full normal position unless said switch machinehas been operatedto the-normal position and-preventingsaidlever beingmoved to thefull reverse position unless said switch machinehas been I .havlng a normal position and var-everse poj first operated to the reverse position comprising; a stickrelay having a pick-up and a stick circuit, said pick-up circuit including the armature of the operating motor of said switch machine when said switch machine is being dynamically braked, and said stick circuit including a contact of said lever -lclosed when said lever assumes the corresponding half position, and means controlled by said-stick relay for permitting said lever to be moved to the corresponding full position. I

3. j In combination; a switch machine for operating railway track switches; a lever having a full normal position, a halt normal position, a full reverse position anda half 'reverse,position for operating said switch machine; and locking means for preventing said lever belng moved to the normal posi- "tion unless said switch machinehasbeen operated to the normal position and preventing said lever being moved to the reverse position unless said switch machine has been first operated to the reverse'position comprising;

a stick relay, a pick-up circuit for said stick relay'in'cluding the motor of said switch machine when the switch machine has completed its stroke and including a contact on said lever closed when assuming the dormsponding half position, a' stick circuit for said relay including'a contact closed when said lever assumes saidcorresponding halfposistick relay for permitting said lever to be H moved to the corresponding full position.

4. In combination ;"a switch machinefor operatingrailway track switches; a lever having a'full normal position, a half normal position, a full reverse position and a half reverse position for operating said switch machine; and lockingmeans .for preventing said lever being moved to the full normal po sition unless said switch -machine. has been operatedto the normal position and preventing-said lever'being moved to the full reverse lposition unless said switch maehineihas been first operated to the reverse position compris ing; a-{stick relay, a pull-down coil vfor said relay for pulling: down the contacts of said relay upon energizati on of said coil, a pick- ;up circuit for said relay including the motor ofsaidswitch machine when said switch mawhen said lever assumes said corresponding sition for operating said switch machine;

half position, a circuit for said zpull-down coil closed when said leverassumes themiddle'positiomand release means controlled by said stick relay for permitting said. lever to and locking means .for preventing said lever .being 'moved ,to :the normal position 'unless said switch machine hasbeenoperated to the normal position and preventing said lever being moved tothe reverse position unless said i switch .machinehas been first operated .to the. reverse position comprising ;v a stick. relay having apick-up anda stick circuit, said pick-up circuit including thearmature of the operatmgmotor of sa1dsw1tclrmach1ne when said switch machine is being dynamically.-

braked, and said stick circuit including a contact o'f-said leverclosed' when said lever applies operating current to said switch machine to operate it to the last operated .-posi tion,.release contacts which ifclosed manifest that 1t is safe to operate said switch, and means efiectlve-when saldstlckrelay 1s enerdeenergizedonly in the event said release'com tacts are closed. 7

16., In a system of the class described; a distant switch machine having a normal circuit and a reverse circuit; a local lever for con-m.

trollingsaid switch machine having a full normal position and a full reverse position,

contacts on said lever for completing said normal clrcult and for completingsaid reverse circuit, a'stick relay havinga pick-upt a circuit energizedby dynamic indication current generated by the inertia of the motor of said switch machine after said switch machine has completed its operating stroke, and a'front contact on said stick relay which if closed permits other traiiic controlling apparatus to be operated which was locked against operation prior to such operation of said switch machine.

7. In a system of the type described, in combination, a'lever, locking means for locking saidlever against movement toward and away from its two extreme full normal and full reverse position, force drop means for :forcing said .locking means 'into each of its" locking positions upon movement of said lever to such positions, a switch machine controlled by said'lever, a stick relay'picked up by dynamic current generated by the motor I of said switch machine when said switch machine has completed its stroke, andmeans for releasing said-locking means effective if said stick relay is energized.

8. In a system of the type described, in

combination, a lever, lockingmeans forlo'cking said lever against movement toward and away from its two extreme full normal and full reverse position, force drop means for forcing said locking means into each of its locking positions upon movement of said lever to such positions, a switch machine controlled by said lever, a stick relay picked up by dynamic current generated by the motor of said switch machine when said switch machine has completed its stroke, an approach section leading to the trackswitch operated by said switch machine, and means for releasing said locking means effective if said stick relay is energized and also-eflective if said stick relay is deenergized and said approach section is unoccupied.

9. In a system of the type described, in

combination, a lever having two intermediate and two extreme positions, locking means for locking said lever against movement from a normal intermediate position to its normal extreme position, a switch machine controlled by said lever, a stick relay picked up by dynamic current generated by the motor of said switch machine when said switch machine has completed its stroke and with said lever assuming an intermediate position, and means for releasing said locking means efi'ective only if said stick relay is energized.

10. In a system of the type described, incombination, a lever, locking means for locking said lever against movement toward and away from its two extreme full normal and full reverse positions, a switch machine con-- trolled by said lever, a stick relay picked up by dynamic current generated by the motor of said switch machine when said switch machine has completed its stroke, and means for releasing said locking means for movement of said lever toward an extreme position effective if said stick relay is energized and effective to release said locking means for movement of said lever away from an extreme position when said stick relay is deenergized and traflic conditions are safe.

trolled by said lever, a stick: relay picked up a by dynamic current generated" by the motor of said switch machine when said switch machine has completed its stroke, means for re-" leasing said locking means for movement of said lever toward an extreme position efl'ec-.

tivc if said, stick relay is energized and efi'ective to release said locking means for movement of said lever away from an extreme position when said stick relay is deenergized and traific conditions are safe, and means effective when said.leverassumes the middle position for effecting deenergizationof said 11..In a system of the type described, in

combination, a lever, locking means for locking said lever against movement from an intermediate toward an extreme position, a switch machine controlled .by said lever, a stick relay picked up by dynamic current generated by the motor of said switch machine when said switch machine has completed its stroke and with said lever assuming an intermediate position, means for releasing said locking means efiective if said stick relay is energized, and means efiective when said lever assumes the middle position for effecting deenergization of said stick relay.

12. In a system of the type described, in combination, a lever, locking means for looking said lever against movement toward and away from its two extreme full normal and full reverse positions, a switch machine con- 

